FEL2012 - List of Authors (Decking, W.)

Paper

Title

Page

Simultaneous Operation of a Multi Beamline FEL Facility

301

B. Faatz, S. Ackermann, V. Ayvazyan, W. Decking, C. Grün, K. Klose, F. Obier, S. Pfeiffer, M. Scholz, J. Wortmann
DESY, Hamburg, Germany
E. Hass
Uni HH, Hamburg, Germany

The FLASH II project will add an undulator beamline and a new experimental Hall to the existing FLASH Facility. In addition to improving the radiation properties of the FEL by using seeding, one of the main goals is to double the beamtime of the facility for users. At the moment, we deliver photon pulses in 10 Hz bursts with up to 800 bunches within each RF pulse. In order not to limit parameter ranges, we will have to give those same tuning possibilities within an RF pulse for each of the users independently. For this purpose, several tests have been performed to determine the limits of the difference in beam parameters which can be delivered. We will show to what extend we can switch fast between two beamlines, how we can change photon pulse length by allowing different charges, have different energy in the two beamlines simultaneously to allow for wavelength scans for the fixed-gap undulator presently built in FLASH, while not interfering with user operation of the new beamline.

TUPD33

Extraction Arc for FLASH II

305

M. Scholz, W. Decking, B. Faatz, T. Limberg
DESY, Hamburg, Germany

FLASH II is an extension of FLASH, an FEL user facility at DESY, Hamburg. It uses the same linear accelerator. A fast kicker and a septum will be installed behind the last superconducting acceleration module at the FLASH linac, providing the possibility to distribute beam to the FLASH undulator beamline and through the new extraction arc into the beamline FLASH2. It is foreseen that at the end of the FLASH II extraction arc the beam can be send into two separate beamlines: The main beamline hosting undulators for SASE and space for HHG seeding, the other might serve later another beamline. The FLASH2 extraction arc was designed to mitigate the effects from coherent synchrotron radiation (CSR) like emittance and energy spread growth. The extraction arc for FLASH2 places also demands on the existing FLASH beamline which are taken into account. The lattice optimization of the arc was done using the program ELEGANT. Start to end simulations for different bunch charges including FEL simulations with GENESIS were carried out to show the feasibility of the FLASH2 extraction arc design.

WEPD07

Status of the FLASH II Project

381

K. Honkavaara, S. Ackermann, V. Ayvazyan, N. Baboi, V. Balandin, W. Decking, S. Düsterer, H.-J. Eckoldt, B. Faatz, M. Felber, J. Feldhaus, N. Golubeva, M. Körfer, M. Kuhlmann, T. Laarmann, A. Leuschner, L. Lilje, T. Limberg, N. Mildner, D. Nölle, F. Obier, A. Petrov, E. Plönjes, K. Rehlich, H. Remde, H. Schlarb, B. Schmidt, M. Schmitz, M. Scholz, S. Schreiber, H. Schulte-Schrepping, J. Spengler, M. Staack, N. Stojanovic, K.I. Tiedtke, M. Tischer, R. Treusch, M. Vogt, H.C. Weddig, T. Wohlenberg
DESY, Hamburg, Germany
M. Drescher, A. Hage, V. Miltchev, R. Riedel, J. Rönsch-Schulenburg, J. Roßbach, M. Schulz, A. Willner
Uni HH, Hamburg, Germany
F. Tavella
HIJ, Jena, Germany

The extension of the FLASH facility at DESY (Hamburg, Germany) - FLASH II Project - is under way. The extension includes a second undulator line with variable gap undulators to allow a more flexible operation, and a new experimental hall for photon experiments. The present FLASH linac will drive the both undulator beamlines. Civil construction of the new buildings has been started in autumn 2011 continuing in several steps until early 2013. The design of the new beamline including the extraction from the FLASH linac and the undulator is mostly finished, and the manufacturing of the components is under way. The mounting of the beamline will start in autumn 2012, and the commissioning with beam is scheduled for second half of 2013. We report here the design of the different phases of the project including the time schedule up to the first user operation.

WEPD09

Scheme for Generating and Transporting THz Radiation to the X-ray Experimental Hall at the European XFEL

389

W. Decking, G. Geloni, V. Kocharyan, E. Saldin, I. Zagorodnov
DESY, Hamburg, Germany

We consider generation of THz radiation from the spent electron beam downstream of the SASE2 undulator in the electron beam dump area. The THz output must propagate at least for 250 meters through the photon beam tunnel to the experimental hall to reach the SASE2 X-ray hutches. We propose to use an open beam waveguide such as an iris guide as transmission line. In order to efficiently couple radiation into the iris transmission line, generation of the THz radiation pulse can be performed directly within the iris guide. The line transporting the THz radiation to the SASE2 X-ray hutches introduces a path delay of about 20 m. Since THz pump/X-ray probe experiments should be enabled, we propose to exploit the European XFEL baseline multi-bunch mode of operation, with 222 ns electron bunch separation, in order to cope with the delay between THz and X-ray pulses. We present start-to-end simulations for 1 nC bunch operation-parameters, optimized for THz pump/X-ray probe experiments. Detailed characterization of the THz and SASE X-ray radiation pulses is performed. Highly focused THz beams will approach the high field limit of 1 V/atomic size.

FROAI01

European XFEL Working Point Optimization and Status

W. Decking, T. Limberg
DESY, Hamburg, Germany

New results of beam parameter measurements at the injector test facility PITZ at DESY, Zeuthen, and the experience of low emittance beam transport in the LCLS called for less conservative assumptions for the beam quality delivered to the SASE undulators. The change in beam parameters and the interests expressed by the users in the first round of workshops concerning the scientific instruments initiated changes in the undulator systems and SASE wavelength ranges. We summarize the present status and highlight recent developments in the European XFEL design.

Slides FROAI01 [14.926 MB]

Paper	Title	Page
TUPD32	Simultaneous Operation of a Multi Beamline FEL Facility	301
	B. Faatz, S. Ackermann, V. Ayvazyan, W. Decking, C. Grün, K. Klose, F. Obier, S. Pfeiffer, M. Scholz, J. Wortmann DESY, Hamburg, Germany E. Hass Uni HH, Hamburg, Germany
	The FLASH II project will add an undulator beamline and a new experimental Hall to the existing FLASH Facility. In addition to improving the radiation properties of the FEL by using seeding, one of the main goals is to double the beamtime of the facility for users. At the moment, we deliver photon pulses in 10 Hz bursts with up to 800 bunches within each RF pulse. In order not to limit parameter ranges, we will have to give those same tuning possibilities within an RF pulse for each of the users independently. For this purpose, several tests have been performed to determine the limits of the difference in beam parameters which can be delivered. We will show to what extend we can switch fast between two beamlines, how we can change photon pulse length by allowing different charges, have different energy in the two beamlines simultaneously to allow for wavelength scans for the fixed-gap undulator presently built in FLASH, while not interfering with user operation of the new beamline.

TUPD33	Extraction Arc for FLASH II	305
	M. Scholz, W. Decking, B. Faatz, T. Limberg DESY, Hamburg, Germany
	FLASH II is an extension of FLASH, an FEL user facility at DESY, Hamburg. It uses the same linear accelerator. A fast kicker and a septum will be installed behind the last superconducting acceleration module at the FLASH linac, providing the possibility to distribute beam to the FLASH undulator beamline and through the new extraction arc into the beamline FLASH2. It is foreseen that at the end of the FLASH II extraction arc the beam can be send into two separate beamlines: The main beamline hosting undulators for SASE and space for HHG seeding, the other might serve later another beamline. The FLASH2 extraction arc was designed to mitigate the effects from coherent synchrotron radiation (CSR) like emittance and energy spread growth. The extraction arc for FLASH2 places also demands on the existing FLASH beamline which are taken into account. The lattice optimization of the arc was done using the program ELEGANT. Start to end simulations for different bunch charges including FEL simulations with GENESIS were carried out to show the feasibility of the FLASH2 extraction arc design.

WEPD07	Status of the FLASH II Project	381
	K. Honkavaara, S. Ackermann, V. Ayvazyan, N. Baboi, V. Balandin, W. Decking, S. Düsterer, H.-J. Eckoldt, B. Faatz, M. Felber, J. Feldhaus, N. Golubeva, M. Körfer, M. Kuhlmann, T. Laarmann, A. Leuschner, L. Lilje, T. Limberg, N. Mildner, D. Nölle, F. Obier, A. Petrov, E. Plönjes, K. Rehlich, H. Remde, H. Schlarb, B. Schmidt, M. Schmitz, M. Scholz, S. Schreiber, H. Schulte-Schrepping, J. Spengler, M. Staack, N. Stojanovic, K.I. Tiedtke, M. Tischer, R. Treusch, M. Vogt, H.C. Weddig, T. Wohlenberg DESY, Hamburg, Germany M. Drescher, A. Hage, V. Miltchev, R. Riedel, J. Rönsch-Schulenburg, J. Roßbach, M. Schulz, A. Willner Uni HH, Hamburg, Germany F. Tavella HIJ, Jena, Germany
	The extension of the FLASH facility at DESY (Hamburg, Germany) - FLASH II Project - is under way. The extension includes a second undulator line with variable gap undulators to allow a more flexible operation, and a new experimental hall for photon experiments. The present FLASH linac will drive the both undulator beamlines. Civil construction of the new buildings has been started in autumn 2011 continuing in several steps until early 2013. The design of the new beamline including the extraction from the FLASH linac and the undulator is mostly finished, and the manufacturing of the components is under way. The mounting of the beamline will start in autumn 2012, and the commissioning with beam is scheduled for second half of 2013. We report here the design of the different phases of the project including the time schedule up to the first user operation.

WEPD09	Scheme for Generating and Transporting THz Radiation to the X-ray Experimental Hall at the European XFEL	389
	W. Decking, G. Geloni, V. Kocharyan, E. Saldin, I. Zagorodnov DESY, Hamburg, Germany
	We consider generation of THz radiation from the spent electron beam downstream of the SASE2 undulator in the electron beam dump area. The THz output must propagate at least for 250 meters through the photon beam tunnel to the experimental hall to reach the SASE2 X-ray hutches. We propose to use an open beam waveguide such as an iris guide as transmission line. In order to efficiently couple radiation into the iris transmission line, generation of the THz radiation pulse can be performed directly within the iris guide. The line transporting the THz radiation to the SASE2 X-ray hutches introduces a path delay of about 20 m. Since THz pump/X-ray probe experiments should be enabled, we propose to exploit the European XFEL baseline multi-bunch mode of operation, with 222 ns electron bunch separation, in order to cope with the delay between THz and X-ray pulses. We present start-to-end simulations for 1 nC bunch operation-parameters, optimized for THz pump/X-ray probe experiments. Detailed characterization of the THz and SASE X-ray radiation pulses is performed. Highly focused THz beams will approach the high field limit of 1 V/atomic size.

FROAI01	European XFEL Working Point Optimization and Status
	W. Decking, T. Limberg DESY, Hamburg, Germany
	New results of beam parameter measurements at the injector test facility PITZ at DESY, Zeuthen, and the experience of low emittance beam transport in the LCLS called for less conservative assumptions for the beam quality delivered to the SASE undulators. The change in beam parameters and the interests expressed by the users in the first round of workshops concerning the scientific instruments initiated changes in the undulator systems and SASE wavelength ranges. We summarize the present status and highlight recent developments in the European XFEL design.
	Slides FROAI01 [14.926 MB]